Mayor Luke Ravenstahl says police Detective Frank Rende should lose his job over his conduct captured on video during St. Patrick's Day celebrations Saturday on the South Side -- even if the detective did not turn on his Taser, as some initially claimed he did in Internet postings.

"My first glance at the video, it is very disturbing. It is something that in my mind shouldn't have happened," Ravenstahl said. "And somebody better give me a real good reason why he shouldn't be fired. It's just unacceptable and that's not the way police should be acting."

In the YouTube video, Rende is seen with his Taser drawn and waving the weapon in his hand. He was working an off-duty private security detail in uniform at the SouthSide Works when he was recorded appearing to hold the weapon to the neck of 27-year-old Mark Keyser Jr., whom he charged with being drunk and disorderly. Keyser can be seen collapsing to the ground. The video of the incident begins at a point after Keyser had left Claddagh Irish Pub, where police say he'd initially been ordered to leave but refused.

The Pittsburgh Police Bureau now says it has determined that Rende's Taser was not activated. Union attorney Bryan Campbell criticized the mayor's comments, saying, "I really think he should have withheld his opinion as to whether or not this employee should be terminated until after he knew all the facts."

Speaking with reporters earlier in the day, Ravenstahl said, "At this point, I see no reason that this individual shouldn't be terminated, and we need to make sure our police officers know that they need to be beyond reproach and doing what they should be doing and protecting the people."

Campbell said city investigators are able to confirm what happened by checking the Taser device. "The way they can tell is, each Taser records usage. In this particular case, there was no use of the Taser. It shows it was not deployed."

But Ravenstahl said, "Regardless of whether it went off or not, he clearly engaged the individual, and went out of his way, 20 or 30 yards down the street to go after this individual. And if the Taser didn't go off, it appeared that he intended for it to go off."

"I'm not an expert in procedures and policies, but I can tell you that I'm sure they were all violated in that case," Ravenstahl said. "To have an officer, you know, literally chase down the individual and use force like he did is something that just will not be tolerated."

Campbell disagrees. "This is a rush to judgment, that all the facts were not established," he said. "There were a lot of facts and a lot of things that took place before that video that he viewed started."

Ravenstahl maintains that Rende's force "clearly" took the man to the ground, "so, regardless of whether or not in my mind the Taser went off, the officer was clearly wrong."

Campbell said he has spoken with Rende. "I think he's very upset, and he has a right to be upset, in that he feels he's being prejudged and he's feeling that the way these things should be handled is there should be an investigation -- that somebody should look at all of the facts before they make a decision."

Following an afternoon meeting with Public Safety Director Michael Huss and acting Police Chief Regina McDonald, Ravenstahl recommended the termination of Rende. "The incident is still being reviewed by the Office of Municipal Investigations and upon completion of this process, a final decision will be made," said Marissa Doyle, a spokeswoman for the mayor.

Pittsburgh Fraternal Order of Police President Michael LaPorte said that any comments are "presumptive" and that "the basis of any investigation is that there are two sides to every story." He said that the video provides a "very limited view" and that it would be "misleading to the public to make any kind of statement."

In the criminal complaint, Rende writes that Keyser got between him and another man he'd ordered to leave Claddagh at the request of a manager. Rende writes that "Keyser then got in between us and put his face six inches from mine and was yelling 'Why does he have to leave?' with spittle spraying in my face." In the same document, Rende says he then told Keyser he had to leave as well, and that he was escorting both men down the sidewalk toward a movie theater with the assistance of other officers.

Rende describes Keyser as screaming questions and being visibly intoxicated, and he wrote that he unholstered his Taser and threatened to use it if Keyser did not leave the area. He said Keyser told him to "go ahead," and, "I then placed the Taser to the side of the actor's neck and pushed the actor away from the bar, not activating the Taser." Rende writes that Keyser "in his intoxicated state lost his balance and fell over a plastic fence."

Court records show that Keyser faces a preliminary hearing on March 26 to answer the charges that Rende filed against him.

Elizabeth Pittinger, director of the Pittsburgh Citizen Police Review Board, said “the entire incident is overwhelmingly unbecoming…it’s a bad image and this bureau doesn’t need any more bad images.”

Pittinger also said she finds it important “for the hundreds of officers out there doing their job properly, to know we recognize that.”

Another video involving Rende and a Taser made news headlines after being posted on YouTube last year. In that incident, baseball fan Scott Ashley was struck with a baton and stunned during a Pittsburgh Pirates game at PNC Park. Ashley later pleaded guilty to charges of simple assault, resisting arrest and a harassment citation.

The World Anti-Doping Agency (WADA) said Sunday it was "very alarmed" by reports of widespread doping by track and field athletes in major competitions including the Olympic Games and world championships.